Neighboring Sunni Arab countries are closely following Iraqi troops and Iranian-backed Shiite militias as they go on the offensive against ISIS.

“Saudi Arabia, UAE, Jordan … see Iran as the major threat and see Iran as taking advantage of the instability produced by ISIS to extend its control and influence over Iraq,” said Ereli, former U.S. Ambassador to Bahrain.

He believes U.S. and coalition airstrikes are not only helping Iraqis, but also the Iranians. “We are really facilitating the further Iranian takeover of Iraq and this is a far cry from what we went into Iraq to do in 2003.”

Critics point out Iran has a more direct role in Iraq’s battle strategy than first believed.

“The reason they are having success in Tikrit … this is simply not an Iranian militia; this is an effort by the Iranians to both gain ground and access to all of Iraq,” said Shaffer, a senior fellow with the London Center for Policy Research.

He believes if Iran firms up its control, this will dissuade Sunnis in Iraq from helping their government stop ISIS.

This situation, Ereli believes, is leaving U.S. allies in a no-win situation. “On the one hand, they are afraid of ISIS because ISIS has them in their sights, so they are working with the United States on air operations and logistical support … but it also makes them afraid of Iran because as the Iraqis push out ISIS, they are being replaced by Shia extremists who are also targeting the Sunni states.”

This is leading to a growing call in the region for moderate states to take the lead in fighting ISIS.

“The Arab states, particularly Saudi Arabia, don’t want another failed state like Somalia on their border,” said Ereli.

Arab leaders “have said they are ready to lead this … the Sunnis have to be the ones to put together a coalition to defeat ISIS,” said Shaffer. “There has to be a balance between the Sunni and Shia elements, otherwise as you see right now” this will lead to a wider regional conflict.